Figure 4. Measurement of BBB permeability using sodium fluorescein in (A) BALB/c and (B) C57Bl/6 mice.

All mice were inoculated subcutaneously with TBEV (100 pfu). BBB permeability is expressed as brain:serum ratio (%). Thirty minutes after intraperitoneal injection of sodium fluorescein, the sera and brains were processed as described in the Material and Methods section and the fluorescence was measured. Asterisks indicate statistically significant increases in brain:serum fluorescence in infected versus uninfected mice (p<0.05).